Photographic developing with addition products to improve image quality



Patented July 11, 1950 PHOTOGRAPHIC DEVELOPING WITH ADDI- TION PRODUCTS" TO IMPROVE IMAGE QUALITY Edward Bowes Knott and J 01m Morgan, Wcaldstone, England, assignors to Eastman Kodak New Jersey Company, Rochester, N. Y., a corporation of No Drawing. Application March 2'7, 1947, Serial 'No. 737,710. In Great Britain April 5, 1946 14 Claims. (01. 955-7) This invention relates to photographic materials 'and more particularly to a method of. improving the quality of the developed images given by photographic silver salt emulsions.

The development of exposed silver'halide photographic emulsions leads to" the formation of a silver image which may vary considerably in colour depending on the type of silver halide, the size ofthe silver halide grain and on the type ofdeveloperfused. GeneraIly the finerthe developed grainthe greater is the tendency for the image to appear brown or green-brown in colour but in many cases it is desirablethat the image should be a neutral grey or black or blue-black.

Another undesirable feature which is often experienced is the liability of the developed image to the effect known as plu'mmin'g or bronzing which occurs during the hot-glazing of prints and produces an adverse effect on image colour and density. v v

A large number of emulsion and developer addition agents have been described which prevent the formation of coloured images or act as andplumming agents but the large majority of such compounds suffer from the disadvantage that they are effective only in silver chloride emul-, sions. Certain agents which are also effective in silver .bromide emulsions have the disadvantage that they are active only after the emulsion containing the agent has been incubatedor held a considerable time after coating. Among these agents are some which, at the same time, are also hardening agents and it is not always possible to obtain the correct'hardness with effective toning.

It is accordingly an object of our invention to provide a novel method of producing developed photographic images of improved quality. "Anothe'r objectis to provide substances which,-.besides acting as antlfogging agents for silver halide emulsions in general, "also' producevery desirable blue-black tones on development. Yet another object isto provide amethod of preventing or re: ducing plummingor bronzing of printsduring the hot-glazing process. Another object is to provide novel photographic materials and developersfor producing developed images of improved quality. These and other objects will be apparentfrom the iollowingspeciflcation. v

W av n w b i d-, e h nmducin eveloped photographic images of improved quality from aphotographic material havinga sensitive s lver, ha d emul n la er. wh c mp ses prQ essin l e-rsa d m te a the esenc Qicompound selected from the group represented by Q the following general formula: y=

wherein X represents a divalent organicgroup:

"and Y represents a member selected from the group consisting of ureidogroups, substituted ureido groups, and nitrogen-containing hetero.-; cyclic groups'having from five to six atoms inv the heterocyclic ring. For example, X may represent a carbon chain suchas alkylene, e. g. meth-. ylene, ethylene, trimethylene, or the like, or substituted alkylene, or methine, or polymethine, or ahetero-carbon chain, or a group comprising a carbocyclic component, e. g. ortho-, meta-,or para-xylene, or a heterocyclic component; 5.1 8 3 represent a ureido-group represented by the for-; W 13 a 1-2 NR 1 .1 \NRI'R" wherein R, R and R each represent a group se-n lected from the class containing hydrogen, alkyl,-v aryl and aralkyl groups, or a'heterocyclic group having the formula:

\N/' wherein Z represents the non-metallic atoms necessary to complete a heterccyclic nucleus con: taining from five to'six atoms in the heterocyclic ring.) e. g. iminazole, dihydroiminazole, benz iminazole, pyrimidine, 'thiodiazine, thiodiazole; or,v h k Vi r "Substances in which Y represents ure'ido or substituted ureido are preferably employed" astheir salts or quaternary salts which are usually more stable than the bases and are water soluble. These salts are usuallyreadily'obtained by heat-' ing'subs'tances of the type: Y

RNH

the quation; it

3 In the above equation the symbols X, R, R, R. have the same meaning as before.

These substances of the invention are added preferably to the emulsion layer or layers but they are also effective, when of the requisite solubility, if added to the developing solution or to other layers carried on the sensitive emulsion support such as the backing layer or supercoat. Alternatively the sensitive layer may he bathedin asol h tion of the agent after exposure but prior to development. The substance is added to the emulsion layer preferably in amountscorresponding to 1-10 g. for every 127 g. ofsilver orto a developer at the rate of 0.2-2.0 g./litre. Higherconcentrations of the agent may be used without increasing the efiect.

. .See Andreasch, Monatshefte der Chemie, 1883,

Many of these agents have the advantage :of

giving neutral images in freshly coated material and it is unnecessary to hold the sensitive -layer for long periods, or to incubate them to produce the effect. The optimal concentration 'for such immediate efiects is'2-'5"g.- agent for every'12'7 g. silver in the emulsion. At lower concentrations these same agents give their best effect on incubating the sensitive layer containing them.

Thecompounds'according to the invention are also'valuable for preventing or reducing the overa'll'silver deposit termed fog which is frequently obtained on developing silver halide emulsion. To produce this antiiogg'ant effect concentrations as low as 0.10 gram per 127 grams of silver may be used, butat these low concentrations there is very littleefiect on'the colour of the image.

The compounds are very effective as antiplumming agentswhen used in any of the ways previously-described or by bathing-the developed imagein a solution of" the compound after fixation. A suitable bath is, for example, an aqueous solution containing from 0.2 to 2.0 grams/litre of the anti-plumming agent.

Example III .S :S -trz'methyIene-bisthz'urom'um bromide I c. c.) and ethyl alcohol (50 c. c.), are refluxed Although in the specification we have described that our invention is by no means'llmited to such baths. Where the term processing" is used in this specification we include any treatment given to the photographic material after exposure and up to the production of the final washed image and, in the case, oi ,printsespecially, including the final, hot-glazing treatment Thus, although the agent is preferably added in the developingsolutions (when .no.t ..alread;y present .in the photographic n aterial) itmay be-added in the fixing bath or prior to washing since sufiicient-oithe compound willbaadsorbed to the-silver grains :to giverthedesir dan ieplumming effect dur ng.hot glazing of theprint. I

Que-invention is illustrated ,by the, following xamples of -eomp unds-w c m y be used v t gether with their methodsof preparation and use:

EXAMPLES c1 1 PREPARATION see Dixon and Taylor, Chem. Soc. 1916, 109, a

for '3 hours. On allowing the liquor to cool the salt crystallized. It formed needles, M. P. 198", after washing with alcohol.

Example IV'.-2 :2 methylenethio-bis-dihydro Ethylenethiourea (2 thiotetrahydroiminazole) (Schacht, "Arch. dervPharm.,;l89.7, 235, 442 Klut,

ibid., 1902,240, 6'75). (10.2 g.), methylene iodide (13.4g.) and ethyl alcohol ('75 c. c. wererefiuxed for 2 hours. Crystallization occurred during the refluxing. The crystals were collected-after coc1-' ing and washed with alcohol. They formed col- Ethylenethiourea '(l0i2 g. ethylenedibromide (9.4 -g.-) and ethyl alcohol-( 0.0. zwererefiuxed for 2 hours and the "precipitated crystals filtered off from the hot liquor. It-formed colourless needies -of no definite melting point. The'base released by 'alkali :had M. P. 203 from methyl alcohol (Schac'ht, loc.=cit.,'p.' 455). 1

Eaiample VI 2 :2 trimethylenethiowisQdihy- ,droiminaeole dihydrobromide OHr 'N N'-.--om l c -'s ci1,'--oH, cH,--s--o .znnr nn-tny Ethyl'ene-thiourea, (1022 g.) dissolved in boiling ethyl "alcohol .(-100 .C. c.) and 1:3-dibromopropane 15.6 o. c.) added and the whole refluxed for3 hours. The salt was collected afterallowing the mixture to cool,,,and .after washing with alcoholhad M. IE-c 224? i v Example ;"VH; 2f z' ethylenethimbis- (-4-methyF- v d-s-onrf-Iom- -s-cf .znm

,Hr-i. NK-on,

2-thio-4-methyltetrahydroiminazole' (Johnson andEdens), J. Amer.- Chem. Soc. 1942, 64, 27027) (3.5 g.) ethylene dibromide (1.3 c. c.) and ethyl alcohol (25 c. 0.) were refluxed for 2 hours On chilling the requireddih-ydrobromide separated. It wascollected; bones 'up wi-th ethyP'al'cdhol-and filtered from the hot liquor. It'formed crystalline powder, M. P. 236. I

Example VIII.--2 :2'-trimethylenethio-bis- (4- methyliminazole) dihydrobromide a white 2 thio 4 methyltetrahydrominazole (3.5 g.) 1:3-dibromopropane (1.55 c. c.) and ethyl alcohol (25 c. 0.) were refluxed for 2 hours. To the cold solution ether was added to precipitate a thick oil which slowly crystallized. The ether-alcohol was decanted, the crystals washed with cold alcohol and dissolved in boiling ethyl alcohol. The slow addition of ether gave colourless needles of the salt, M. P. 177.

Example IX.-D isodium 2:2'-et hylenethio bis- (4-amino-6-hydroxypyrimidi1re) C-SQHr-CHr-SC BrHgN NHzBr Ethylthiourea (5.2 g.), ethylene v dibromide (2.5 c. c.) and ethyl alcohol (20 c. 0.) were re.- fluxed for 1 hour. Dry ether Was slowly added with shaking to give a mass of white crystals. They were collected, washed with alcohol-ether (1 :2) then with ether. M. P, 92". They are very hydroscopic. p

Example XI .-S:S-ethylene bis N :N '-diethylthiuronium bromide CaHaNH NHCQHE c-s-oH=cHl+s-o BrHNCzHr, NHCzH Br (Noah, Ben, 1890, 23, 2198). S-diethylthiourea (6.6 g.), ethylene dibromide (2.5 c. c.) and ethyl alcohol (20 c. c.) were refluxed for 1 hour. Dry ether was slowly added with shaking to give a mass of crystals. They werecollectedywashed with alcohol-ether (1:2) then with ether. M. P.

186. Example Xpl' I .S :S -trimethylene-b;is -N :N -triethylthiuronium bromide I CzHaNH NHCzHs Example XIIL-S:S-ethyZene-bis-N:N"-triethylthiuronium bromide NHCzHsBr aqueous alcohol, as fine white needles M. P. 231.

Example XVIII.-.2 :z etnyzenemiois- (5 -tlliol- Triethylthiourea (8.0 g.), ethylene dibromide (2.5 c. c.) and ethyl alcohol (20 c. 0.) were refiuxed for 2 hours, chilled and the salt precipitated as an oil with dry ether. The ether was decanted and the process repeated shaking vigorously after each addition. The thick oil so obtained crystallized slowly on standing under ether. It was collected, drained well, dissolved in ethyl alcohol and reprecipitated with ether. It formed white needles, M. P. 130-132". I Example XIV.-S:S'-o-xylylenyl-bis-thiuronium bromide NH: OH1S-C NHiBr NH: CHr-S-C NH BI o-Xylylenedibromide (5.3 g.), thiourea (3.0 g.'), and ethyl alcohol (25 c. 0.) were refluxed for minutes. Ether was added to precipitate an'oil which crystallized. It formed soft needles, M. P. 225-226 after recrystallization from a little water and acetone. Example XV.-S:S-ethylenethi0-bis-(l-methyldihydroiminazole) di-p-toluenesulphorvate on warming 2:2'-ethylenethio-bis-dihydroiminazole (1 mol.) with methyl p-toluenesulphonate (2 mol.) on the steam bath a vigorous reaction ensued and a thick oil remained; This is completely water soluble and is believed to have the above constitution.

Example XVI.--S:S'-ethylene-bis-N-phenyl-N methylthiurom'um bromide N-phenyl-N-methylthiourea (3.3 g.) ethylene 'dibromide (1 c. c.) and ethyl alcohol (100. 0.)

Example XVII .-4:4-ethylenethio bis (4:6-di- 2:4:6-trithio-1:3zfi-thiodiazine (0.97 g.) and ethylene dibromide (0.21 c. 0.) were dissolved in ethyl alcohol (l0 c. c.) and refluxed'for 1 hour during which fine white crystals, were formed. They were filtered oil, and recrystallized from 1 :3 :4-thiodia'zole) 2:5-dithiol-1:3:4-thiodiazole (3.0 g.) was dissolved in ethyl alcohol (15 0'. c.)..and-.ethylene di- 7 bromide (0.860. c.) added. After refluxing for hours, during which fine white crystals appeared;-'the mixture was cooled and filtered. The solid was "recrystallized from aqueous alcohol as white prisms M.iP. 254.

EXAMPLES OF USE Example A.5 g. of the compound'of Example I added to 5 litres of a fine grained positive type emulsion (containing the equivalent of 200 g. sil ver nitrate) changes the normal olive brown tone of the blacks to blue black when developed in a normal metol-hydroquinone developer.

Example B.2 g. of the compound of Example II added to 5 litres of this emulsion gave almost neutral blacks whil 5 g. in the same quantity gave pronounced blue blacks. Incubation for 3 days at 50 C. of the coated-emulsion caused a further change of tone towards the blue shades.

Example O.5 g. of the compound of Example IIIadded to 8 litres of a chloride emulsion (containing the equivalent of 200 g. silver nitrate) changed the brown tone of the blacks to blueblack.

Example D.--The addition of 1 g. of the compound of Example II per litre of normal metolhydroquinone developer when developing the fine grained positive emulsion, as used in Examples A and '3, gave blacks only faintly brown, compared with the pronounced olive brown tones normally obtained.

Example E.5 g.of the compound of Example III added to 5 litres of the fine grained positive emulsion gave the blue tone to the black when developed in a normal metol-hydroquinone de-'- veloper.

Example F.5 g. of the compound of Example IV added to 5 litres of the-fine grained positive emulsion produced very strong blue-black effect.

Example G.-3 g. of the compound of Example V added to 5 litres of the emulsion used for the previous example reduced the brown tone of the blacks, while 5 g./5 litres gave nearly neutral blacks. Incubation of the coated plates for 3 days at 50 C. resulted in a further effect giving blueblack on development.

Example H.5 g. of the compound of Example VI added to 5 litres of the same emulsion reduced X added to 5 litres of the emulsion used above gave almost neutral blacks on development; after incubation for. 3 days at 50'C.the blacks obtained were slightly bluish.

I ExampZe M.5 g. of the compound of Example XI added to 5 litres of the emulsion gave a similar resultto Example L initially, but after incubation very strong blue black tones were obtained on development.

Example N .5 g. of the compound of Example;

XIII added to 5litres of the .emulsion gave almost identical results with those in Example L.

Example O.5 g. of the compound of Example XIV addedto 5 litres of the emulsion gave neutral blacksonidevelopment;

.Example P.-''5 g'. ofthe compoundof Example XV added to 5 litresof thesame emulsion gave strong blue-black tones Example Q 701) A silver chloro+bromide emulsion coated on paper was exposed to a step wedge, developed, and fixed.

(b) The samepaper-was treated as above but with the addition of 1 g. of the compound o fgExample II to 1 litre of developer.

'(c) The same paper was treated as in (a) but after fixation the paper'was bathed in a. solution of 5g. of the compound of Example I in 109 c. c. water for 5 minutes.

On hot-glazing, the papers treated according to (b) or (0) gave very deep blacks whilst the untreated paper (a) showed a big'loss of density. 'Example'R.-'Onsubstituting the compound" of Example XIII for that of Example II in Example Q (1)) asimilareffectwas obtained. i v

Example. S.On substituting the compound of Example V for that of Example II in Example Q (o) a similar effect was obtained.

Example T.- A highspeed panchromatic emulsion was coated: (a) as such with the usual hardener; (b) as (a) but with the addition of 0.25 g. of the compound of Example I! per 5 litres of emulsion containing the equivalent of 200 g. silver nitrate. On forced development or after incubation the coating (a) showed a much higher fog than did (b) Other agents'such as those of Examples II, V, VI, VII, X, XI, XII, etc., added to the emulsion at the samerate also showed pronounced antifog} ging and stabilizing properties.

Example U.A silver chlorid emulsion was divided and one part coatedon paper. The other part was melted and to an amount of the emulsion containing the equivalent of 200 g. silver nitrate was added 8 g. of the compound of Example II and the emulsion coated.

After exposure and processing, stripsv of the two coatings were hot glazed. Those strips containing the agent showed a much blacker and high maximum density than the strips coated with the untreated emulsion.

Example V.Substitution of the same quantity of the compound of Example XVII for the compound of Example II in the experiments of Example U gave similar results. 7

Example W.'Substitutionof the same quantity of the compound of Example XVIII for the compound of Example II in the experiments of Example V gave'similar results and the increase in maximum density was particularly good in this case. l

Having thus :described ourinvention what we claim is;

'1. Method of producing developed photo-- graphic images of improved quality from a photographic material having a sensitive silverhalide emulsion layer comprising developing the said material in the presence of a compound selected from the grouprepresented by the following general formulae:

where X represents a divalent organic group selected from the class consisting of v,alkylene and where X represents a divalent organic group selected from the class. consisting of alkylene and xylylene, R, R and R" each represent groups selected from the class containing hydrogen, alkyl, aryl and arylkyl groups, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from five to six atoms in the heterocyclic ring.

3. Method of producing developed photographic images of improved quality from a photographic material having a sensitive silver halide emulsion layer comprising developing the said material in a developing solution containing a compound selected from the group represented by the following general formulae:

where X represents a divalent organic group selected from the class consisting of alkylene and xylylene, R, R and R" each represent groups selected from the class containing hydrogen, alkyl, aryl and arylkyl groups, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from five to six atoms in the heterocyclic ring.

4. A photographic material comprising a support having thereon a light-sensitive layer and a layer containing a compound selected from the group represented by the following general formulae:

where X represents a divalent organic group selected from the class consisting of alkylene and xylylene, R, R and R" each represent groups selected from the class containing hydrogen, alkyl, aryl and arylkyl groups, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from five to six atoms in the heterocyclic ring.

:10 .1 5;,Agphotographic material comprising a sensi-- tive' silver halide emulsion layer containing a compound selected from the groups, represented by the following general formulae:

1 RN\ /NR o -s-x s-o RIRIIN I I and p where X represents a divalent organic group selected from the class consisting of alkylene and xylylene, R, R and R" each represent groups selected from'the class containing hydrogen, alkyl, aryl and-arylkyl groups, and Zrepresents the non-metallic atoms necessary to complete a heterocyclic *nucleus containing from five to six atoms in the heterocyclic ring.

6. The method of producingdeveloped photographic images of improved quality from a photographic materialhaving a sensitive silver halide emulsion layer comprising developing said material in the presence of a quaternary salt of a compound having theformula:

where X represents an alkylene group.

7. The method of producing developed photographic images of improved quality from a photographic material having a sensitive silver halide emulsion layer comprising developing said material in the presence of a compound having the following formula:

8. The method of producing developed photographic images of improved quality from a photographic material having a sensitive silver halide emulsion layer comprising developing said material in the presence of a quaternary salt of a compound having the formula:

HN NH RHN HR Where X represents an alkylene group and R represents an alkyl group.

9. The method of producing developed photographic images of improved quality having a sensitive silver halide emulsion layer comprising developing said material in the presence of a compound having the formula:

where X represents an alkylene group.

11. The method of producing developed photoage-14,650

11 graphic images of improved quality having a sensitive silver halideemulsion' layer comprising developing said material in the presence of a compound having the formula:

12. A photographic material comprising a sensitive silver halide emulsion layer containing the quaternary salt of a compound having the following formula:

HN 5 NH v c---s-x--s--o HiN NH:

where X represents anialkylenelgroup.

13. A photographic.- material comprising a sensitive silver halide emulsion layer containing the quaternary salt'of atcompound having the following formula:

where X represents an alkylene group. and R represents an .alkyl group.

' REFERENCES CITED The following references are of record in the file of this patent;

UNITED STATES PATENTS Number Name Date 2,124,159 Weyde July 19, 1938 2,453,087 7 Dersch'et alt Nov. 2, 1948 20 2,465,149 Dersch et al. Mar. 22, 1949 OTHER REFERENCES Kraft: Zeit. fiir Wiss; Phot., Bd. 31, Heft 1-2, May 1932, pages 3295120 364, pages 3535 and 355 25 Cited. 

1. METHOD OF PRODUCING DEVELOPED PHOTOGRAPHIC IMAGES OF IMPROVED QUALITY FROM A PHOTOGRAPHIC MATERIAL HAVING A SENSITIVE SILVER HALIDE EMULSION LAYER COMPRISING DEVELOPING THE SAID MATERIAL IN THE PRESENCE OF A COMPOUND SELECTED FROM THE GROUP REPRESENTED BY THE FOLLOWING GENERAL FORMULAE: 